Javascript – Object constructor

In JavaScript, objects are king. If you understand objects, you understand JavaScript.


In JavaScript, almost “everything” is an object.

  • Booleans can be objects (if defined with the new keyword)
  • Numbers can be objects (if defined with the new keyword)
  • Strings can be objects (if defined with the new keyword)
  • Dates are always objects
  • Maths are always objects
  • Regular expressions are always objects
  • Arrays are always objects
  • Functions are always objects
  • Objects are always objects

All JavaScript values, except primitives, are objects.

The examples above are limited in many situations. They only create a single object.

Sometimes we like to have an “object type” that can be used to create many objects of one type.

The standard way to create an “object type” is to use an object constructor function:

Examples

Using prototypes:

 

Hiding “color” (somewhat resembles a private member variable):

 

Usage:

 

Another example:

Another example:

 

Reference

https://www.w3schools.com/js/js_object_definition.asp